professor of medicine and fox news contributor. what do we need to know about this variant? >> good morning, dana. this variant is called the 1617.2. the delta variant. what's concerning is it's 60% of the cases in the united kingdom. bad news is that the pfizer or moderna shot if you only have one dose gives you 33% protection. that's laboratory estimate. but after your second dose two weeks after you are over 80% protected. what does that mean? that means if you are fully vaccinated with an mrna vaccine against the variant the chances are high you won't get it and if you got it you would get only a mild case. that's why the call to arms if you haven't been vaccinated, get vaccinated now. get fully vaccinated as soon as possible. the chances are this variant will take hold here. it is already started to spread in the united states. >> dana: call to arms indeed. guns out to get your shot.